1. Field of the Invention
The present invention relates to a liquid crystal display device and a method for forming an alignment film. In particular, the present invention relates to a liquid crystal display device with at least a guarding wall to go with the formation of the alignment film.
2. Description of the Prior Art
The alignment film is considered as one of the crucial components in the liquid crystal display device. The alignment film is placed on the substrate of the liquid crystal display device, in order to construct the pretilt angle of the liquid crystal molecules, which is the kernel component of the liquid crystal device. Only when the liquid crystal molecules in the liquid crystal display panel have correct pretilt angle will the liquid crystal molecules twist correctly in accordance the external electric field to create the required images.
The process to form the alignment film requires rollers with specially designed patterns to correctly transfer the alignment film solution (the Pi solution) onto a pre-determined location of the panel on the substrate. FIG. 1 illustrates rollers with specially designed patterns to print the alignment film solution in the prior art. As shown in FIG. 1, the roller 110 has patterns 113 corresponding to a location of the panel on the substrate, so the alignment film solution 111 is transferred onto the substrate 114 by contacting the correct location on the substrate 114 to avoid any undesirable transfer of the alignment film solution 111 onto incorrect zones on the substrate 114, for example, the frame adhesive zone 115 because the alignment film solution 111 may compromise the function of the frame adhesive and jeopardize the quality of the liquid crystal display products.
However, liquid crystal display panels of various forms and of different sizes all require exclusive rollers of particular patterns in order to correspond to the unique patterns of the liquid crystal display process panels on the substrate. In particular, reserved spaces are needed for the frame adhesive and the external connectors on the liquid crystal display panels, so liquid crystal display panels of different specifications require exclusive rollers of particular patterns. Besides, with the larger and larger sizes of the liquid crystal display panels, for example those above G6 generation, it is harder and harder to make the corresponding unique patterned rollers. Solutions such as piecing up, in which smaller pieces are jointed together to obtain a larger, complete one, have been proposed. However, it adversely affects the production of the liquid crystal display panels. This process is neither economical nor cost-saving.
Accordingly, a novel substrate for the liquid crystal display process is needed to use non-exclusive rollers for various sizes and specifications. The alignment film solution can be correctly transferred onto a pre-determined location of the panel on the substrate by a simplest and easiest method without interfering with other regions on the substrate.